Rochester, NY: More than 80 percent of US adults favor legalizing cannabis for therapeutic purposes, according to the results of a nationwide Harris poll.

Eighty-one percent of respondents, including super-majorities of Democrats, Republicans, and Independents, expressed support for legalizing marijuana for medical treatment. The result is an increase of seven percentage points since Harris pollsters last posed the question in 2011.

Forty-nine percent of respondents said that they believed cannabis should be legal recreationally (up from 42 percent in 2011). Majorities of Democrats (58 percent) and Independents (55 percent) backed legalization, but only 27 percent of Republicans did so. Several other recent polls, including those commissioned by the Pew Research Center, Fox News, and the General Social Survey, have shown majority support for the adult regulation of marijuana.

A majority of Republicans (51 percent) acknowledged that marijuana policy should be decided at the state level and not by the federal government. Forty-seven percent of Independents, but only 37 percent of Democrats, shared this position.